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The present embodiment related to hearing assist devices such as hearing aids, headset, and the like, and are more particularly directed to improving the ability of such devices to present a selection of sounds based on the directionality of the sound source.
Contemporary hearing assist devices take many forms that amplify sounds external from the wearing of the device and then present the amplify to the wearer. Moreover some of these devices also use technology to prevent or lower the devices use a bandpass filter to pass only the speech frequency portion of the external sound to the wearer of the device, thereby attempting to reduce or eliminate the chance that the user will hear sounds other than speech. As another example, some hearing assist devices use adaptive signal processing technology to remove interfering sound regardless of the direction of the sound. This devices implement a single microphone to achieve this functionality, and are sometimes sold in airports.
By way of further background, U.S. Pat. No. 4,449,018, entitled xe2x80x9cHearing Aid,xe2x80x9d issued May 15, 1984 (xe2x80x9cthe ""018 patent), and the discusses a device for providing a directional sense to a human based on sound originating in different vertical locations relative to the human. More particularly, the ""018 patent discloses a structure that fully encloses the pinna of the human ear. Two microphone are mounted externally to the enclosing structure and vertically with respect to one another. Similarly to transducers (i.e., speaker) are mounted internally within the enclosing structure and also vertically with respect to one another. Finally, a circuit to process signals from the microphone, or from other sources, so that sound signals are presented to the two different vertically-oriented speakers, thereby providing dissimilar sounds to the ear based on sound emitted in different vertical planes. The ""018 patent also very briefly discusses an approach were the above-described structure is duplicated for both ears, that is, such that each ear has a two-microphone, two-speaker structure, and each structure then provides vertically differing sounds to a respective ear of the person wearing the structures.
While the above-described systems provide certain advantages to limit the scope of sounds provided to the device wearer, the present inventors have recognized that these devices provide drawbacks in that they do not fill a still existing need in the field of hearing assistance. Specifically, many prior art devices do not account for the directionality of sounds relative to the wearer of the device, while the present inventors have determined that by locating the direction of the sound source(s), the sound actually presented the user may be modified in view of that directionality. Further, if the sound presented to the wearer does not account for directionality of the desires of the user, the resulting presented sounds may be distracting and indeed may be a limitation on the ability of the wearer to appreciate information provided to the wearer due to the influence or emphasis that directionality otherwise imparts on sound information. Further, this loss may be complicated by other device limitations. For example, in the case of a typical amplify-only hearing aid, the presence of the physical hearing aid in the ear canal disrupts the focusing and sound directionality (i.e., horn) aspect of the outer ear and ear canal. As a result, the ability to concentrate upon sound is lost. Moreover, often the fit of the hearing aid changes over time, which may further distort or affect the loss of directionality. Lastly, in connection with its dual-ear structure, the ""018 patent purports to address different sounds appearing in the same horizontal plane as the human wearing the device; however, the ""018 patent is silent on what functionality is used to accomplish this result, or the way in which it is achieved.
In view of the above, there arises a need to address the drawbacks of the prior art and to provide an improved hearing assist device which presents its wearer with a sense of directionality or choice of directionality, as is achieved by the preferred embodiments discussed below.
In the preferred embodiment, there is a hearing assist device for a person. The device comprises a speaker device for presenting sound to an ear canal of the person and circuitry for identifying a specified area relative to the person. The device further comprises a first microphone for providing a first sound signal in response to a first sound source located inside the area and in response to a second sound source located outside the area. Further, the device comprises a second microphone for providing a second sound signal in response to the first sound source and the second sound source. Still further, the device comprises circuitry for determining a position of the first sound source and the second sound source in response to the specified are, the first sound signal and the second signal. Finally, the device comprises circuitry for outputting a processed signal in response to the position. In operation, the speaker device is operable to present processed sound to the ear canal in response to the processed signal, wherein the processed sound represents a different suppression of sound from the second sound source relative to sound from the first sound source. Other circuits, systems, and methods are also disclosed and claimed.